Wordpress theme, theme payment coding need adjustments and rewriting

General information for the website: Job listing website
Kind of development: Customization of existing website
Description of every page/module: Theme is 9-5 from theme forest.
Theme payment setting to set for paypal payments for each job posting.( charges are changable in the theme setting)
this need additional payment options so will need to be changed with the options to have :
a) a monthly subscription for x amount ( amount changeable )
b) payments for each job
c) annual subscription for x amount ( amount changable )
d) every [x] monthly subscription for x amount ( amount changable )

Description of requirements/features: a rewrite of code, plus additional code and bug checks for new monthly subscription required
Extra notes:

[currently with the theme is very easy to change payment it is already set up but only for per job posting ,not monthly or annualy}